Combined annealing and muffle furnace.



-A. KINNEAR.

oomsmen ANNEALlNG AND MUFFLE FURNACE.

APPLICATION FILED MAR. H, 1915.

Patented Feb. 1, 1916.

2 SHEETS-SHEET 1 A. KINNEAR.

.11 COMBINED ANNEALING AND MUFFLE FURNACE.

APPLICATlON FILED MAR. H. 1915.

1,170,164. Patented Feb.1,1916.

2 SHEETS-SHEET 2.

THE COLUMBIA PLANOGRAPH co., WASHINGTON, D. c.

err

I ALEXANDER KINNEAR, 0E TOLEDO, oHIo.

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COMBINED ANNEALING AND MUEELE EUENAcE.

Specification of Letters Patent.

Patented Feb. 1, 1916.

Application filed March 11,1915. Serial No. 13,578

T 0 all whom it may concern:

Be it known that I, ALEXANDER KINNEAR, a citizen of the United States, residing at Toledo, in the county of Lucas and State of Ohio, have invented new and useful Improvements in Combined Annealing and Mufile Furnaces, of which the following is a specification.

My invention relates to a combined annealing and muflie furnace-and has for its object to provide a furnace ofthe kind that is efficient and economical in operation and convenient for filling and emptying, and that is readily used as a muflie-furnace after being usedfor annealing.

I accomplish these ob ects by theconstruction, arrangement and combination of parts as hereinafter described and illustrated in the drawing, in which Figure 1 is a top View of a furnace constructed in accordance with my invention. Fig. 2 is a vertical section of the same on line w--w of Fig. 1. Fig. 3 is a side elevation of the same, and Fig. 4 is a similar view at right angles to the view shown in Fig. V

In the drawings F designates a furnace comprising an outer cylindrical casing 1,

' casing 5.

having a bottom closure 2 anda top end closure 3 provided with a central flue hand an inner cylindricalcasing 5 concentric to the outer casing 1 and mounted on the bottom 2 at its lower end, and having itstop er 1 gl provided with a closure 6.

The inner casing 5 is divided into a plurality of heating chambers 7 by circularrpartition floors 8 which are preferably constructed of suitable metallic frames filled in with fire clay to form a flat annular surface 9 on their top sides and having their lower sides spherically convexed. At their outer edges the floors 8 are attached to and suitably supported by the inner wall of the'inner Below and near each floor 8 the inner casing 5 is provided at regular intervals with a plurality of upwardly and outwardly inclined ports 10 into theannular flue chamber 11 between the inner and outer casings 1 and 5. =1

On diametrically. opposite sides both the outer and inner casings are provided with door openings for each chamber 7 and to opposite sides of these openings in the outer casing are hinged companion doors 13 which have inner portions 14 spaced from and supported by the doors 13 and adapted when the doors 13 are closed together to close the door openings of the inner casing 5.

Between the doors of such chamber 7 the outer casing is provided with one or more ventilator openings 15 opposite each chamber 7 adapted to be closed by fire clay plugs 16.

lhe top end 3 of the outer casing has mounted'thereon concentric thereto an an nular gas pipe 17 having a branch 18 for connecting it with a gassupply, and branches 19 extending down the outer wallof the casing 1, he to each chamber 7, and through the outer and inner casings to' connection with an annular or doughnut burner 19 secured centrally to theunder or convex side of each partition 8, each branch being provided with a controlling valve 20. The pipe 17 is also provided with a branch 21 which is connected to an annular burner 21 at the bottom of the annular chamber 11 between the inner and outer casings, the branch 21 also being provided with acontrolling valve 20. a

At intervals of 90 of the periphery of the outer casing 1 of the furnace is secured longitudinally and vertical, to the outer wall of the casing the toothed racks 22. p

The furnace thus constructed is telescopically mounted in a mufile pit 23 of' suitable diameter and depth to receive the entire length of the furnace, and to raise and lower the furnace from and into the pit 23, there is provided for each rack an inteimeshing chain of gear wheels 24, and'ea'ch of the chains of gears being mounted and operated equally and simultaneously from a common source (not shown) the. furnace is raised from and lowered into the pit 23 as desired.

In operation, the furnace having been filled with articles to be annealed and heated to a vdesired degree and for a length of time to'anneal the articles, the furnace is lowered into the 'niulile pit 23, the valves of the branches 20 and 21 are closed and a cover 25 is placed over the furnace resting on the top of the wall of the pit, and the furnace is left to gradually and slowly cool. When cooled the cover 25 is removed and the furnace is raised until the top chamber 7 is at a height above the floor 26 convenient for emptying and refilling. When the top ch am: her 7 is emptied and refilled the doors l3'of that chamber are closed and the furnace is again raised until the next lower chamber 7 is brought into the emptying and filling position, which being tlso emptied and refilled, the doors are closed andthefurnace is again raised to bring the third chamber into the filling po ition,- and so on until all thechambers are emptied and re-filled. The burners are then lighted in each chamber and as soon as the heat has been raised in the topchamber to the desired degree thegas isgradually turned down. from. the top chamber to prevent raising the heat in the upperchamber above the desired annealing temperature, and when. the desired annealing. heat has been maintained. in all the chambers for the desired length of time, the burners-are all turned out andcthe furnace islowered, into the pit, the cover 25 is placed over the mouth of the pit, and the furnace is. left. to. slowly cool as aforesaid. If it is desired to prolong the coolingprocess the burner 21 is lighted before the'furnace is lowered andleft burning lowfor a time afterthe cover 25 is placed inposition covering the pit..

Preferably, pyrometers ,(not shown) are attached toeach chamber 7 whereby the exact degree of heat in any chamber may be observed and in the event that the degree-of heat in the, upper chambers cannot be prevented from going abovea desired maximumtemperature by turning out theburners of such upper chambers, ports 15 may be opened by removing plugs 16 until allthe chambers are brought to the desired degree of heat without danger of producing any sudden lowering of temperature in any chamber.

By providing a series of furnaces constructed in accordance with my invention-of sufficient capacity to anneal the daily out put of a factory, while some of the series are being emptied and filled, others may be heated and others may be slowly cooling.

It is manifest that in embodying my invention various minor changes in the con struction shown and described may be made without departing from the principle of its construction and operation, and I therefore, in the embodiment thereof, do not limit myself excepting as expressed in the claims.

By constructing a furnace in accordance with my invention I avoid the extra labor and expense of transferring the annealed articles from an annealing furnace to a separate muffle furnace, and all of the annealing chambers are made convenient for filling and emptying,

What I claim to be new is- 1. In a combined annealing and muffle furnace, the combination of a movable furnace body comprising an outer casing having a bottom end closure and a top closure provided with a central flue, an inner casing within the outer casing and supported on its bottom. end and forming with the outer casing a chamber around the inner casing between the casings,said inner casing being provided with a plurality of divisional floors dividing the innercasing into a plurality of heating chambers, and said inner and outer casings being each provided with door zopenings' oppositeeach chamber, doors hinged tothe outer casing and having inner oifset portions adapted when the doors are closed in the door openings of the outer casing to close-the-dooropenings of the inner casing, agas supply pipe mounted on the top of-the outer casing and having a branch adapted tobe flexibly connected with a gas supply, a plurality ofburners one connected to the under side of each floor partition of the inner casing, branch pipes connecting each burner with the supply pipe, a mullie pit below and adapted to telescopically receive the furnace body, means to raise'and lower the furnace body from and into the pit and a cover adapted to close the top of the pit with the furnace therein 2. In a combined annealing and muilie furnace, the combination of a movable furnace body comprising an outer casing having. a bottom end closure and a top closure provided with a-central flue, an inner casing within-the'outer casing and supported on its bottom end and forming with the outer casing achamber around the inner casing between the casings, said inner casing being provided with a plurality of divisional floors dividing the inner casing into a plurality of heating chambers, and with vent ports from each chamber into the chamber between the casings, and said inner and outer casings being each provided with door openings opposite each chamber, doors hinged to the outer casing and having in ner offset portions adapted when the doors are closed in the door openings of the outer casing to close the door openings of the inner casing, a gas supply pipe mounted on the top of the outer casing and having a branch adapted to be flexibly connected with a gas supply, a plurality of burners one connected to the under side of each floor partition of the inner casing, branch plpes connecting each burner with-the supply pipe, a muflie pit below and adapted to my hand at Toledo, Ohio, this 6th day of telescopically receive the furnace body, March, 1915, in the presence of two submeans to raise and lower the furnace body scribing Witnesses. from and into the pit and a cover adapted ALEXANDER KINNEAR. 5 to close the top of the pit with the furnace In presence of 1 therein. ALBERT T. GooRLEr,

In Witness whereof I have hereunto set E. H. ECKERT.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0. 

